Fire-extinguisher.



H. W. DOUGHTY.

FIRE EXTINGUISHER.

APPLICATION FILED FEB. 10.1913. RENEWED APR. 12. 1915.

1,157,090. Patented OOt. 19, 1915.

. v a M 7 J0 attoznuao HOWARD W. DOUGHTY, 0F AMHERST, MASSACHUSETTS. I

FIRE-EXTINGUISHER Specification of Letters Patent.

Application filed February 10, 1913, Serial No. 747,510. Renewed April 12, 1915. Serial No. 20,945.

To all whom it may concern Be it known that I, HOWARD W. DOUGHTY, a citizen of the United States, residing at Amherst, in the county of Hampshire and State of Massachusetts, have invented certain new and useful Improvements in Fire- Extinguishers; and I do declare the following to be a full, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use the same.

This invention relates to a portable automatic fire extinguisher of the sprinkler type.

One object of the invention is to provide a self contained automatic sprinkling fire extinguisher which requires no central reservoir, no elaborate system of pipe connectioneach unit being complete in itself and absolutely independent of every other unitand which is very simple in construction thereby insuring ch'eapness of manufacture and in which the cost of installation is only that incidental to hanging the extinguisher to a suitable support.

Another object of the invention is to provide a fire extinguisher in which an extinguishing liquid of low boiling point is employed surrounded by a compound or material which produces sure at a predetermined temperature.

Another object is to provide a fire extinguisher, the nozzle of which is closed by a cap sufficiently strong to resist low pressure and adapted to be ruptured when a predetermined high pressure is reached within the vessel having the nozzle thus producing a seal which will break at a given pressure.

With these and other objects in View, the invention consists of certain novel features of construction, and the combination and arrangement of parts as will be more fully described and claimed. In the accompanying drawings, Figure 1 represents a vertical longitudinal section of one form of fire extinguisher constructed in accordance with this invention; Fig. 2 is a horizontal section thereof taken on the line 22 of- Fig. 1.

In the embodiment illustrated a s mple form of the invention is shown comprislng'a container consisting of an outer shell 1 which is a good conductor of heat and which may be of any suitable or desired shape, the form here shown being that of a cylindrical body having an inverted truncated cone what gas under high presconsiderable radius.

shaped bottom 2 and a top 3 having a central opening for a purpose to be described.

11 lnner casln 5 is arranged within the shell 1 preferab y conforming in outline to the shape of said shell 1 and spaced a suitable distance therefrom to form a liquid .contaimng chamber 6 of restricted capacity.

A tube 9 extends through the opening 4' inthe top 3 of the shell 1 and is secured in said opening by any suitable means. This tube 9 is preferably tapered at its upper end to form a restricted jet or nozzle 10 and the lower end thereof extends nearly to the bot tom of the casing 5.

A spreader 11 which may be variedsomeshown in the form of a disk having a depending central projection 7 on its lower face which is spaced slightly from the end of the nozzle l0oand against which the liquid discharged from said nozzle is designed to impinge, said disk being held in fixed position by means of wires 12 which connect it with a collar 13 fixed on the tube 9 outside the container. The inner face of the disk may be varied to regulate the spreading action of the liquid or vapor sprayed through the nozzle 10, the shape here shown being especially adapted to spread the liquid discharged thereagainst.

The nozzle 10 is normally closed by a thin Patented Oct. 19, 1915.,

so I

with the condition of service is here pressure has been developed to sprinkle a This closure 8 may be held in place around nozzle by any suitable means.

Thetop of the shell 1 is provided with an opening 15'closed by a plug 16 and is designed for filling the container when necesthe delivery end of the' sary with the liquid to be used. The casing sired spacers may be employed.

. monia gas produced becomes insoluble in ever,

- tainer until the pressure 5 is spaced from the inner face of the shell 1 by spacing lugs 17 which are here shown projecting laterally from such casing 5 and engaging the inner face of the shell 1 but it is obvious that any other suitable or de- A suitable fire extinguishing liquid is used in the inner vessel 5, carbon tetra-chlorid being especially adapted for this purpose because of its low boiling point and its volatility. The restricted chamber 6 between the casing '5 and shell 1 is supplied with a substance which when heated produces a gas of high pressure very rapidly and the gas from which does not condense as-the vapor of a boiling liquid would on being brought into contact with the cooler liquid in the inner receptacle. Concentrated ammonia solution has been found to be efiicacious as the pressure producing substance but other materials may be used. One of the advantages in using ammonia solution is that when ammonia solution is heated the amwater except under great pressure and the development of the pressure produced is very rapid and the pressure continues even after the source of heat is removed as the gas is not immediately reabsorbed thereby resulting in a very great increase of sensitiveness. This sensitivenessmight, howbe an objection were means not proto retain the liquid within the conactually reached a considerable amount for it might be that in warm weather enough pressure might be developed to cause a loss of extinguishing liquid even though no sprinkling eifect would occur. This renders the use of a seal on the nozzle of the container,which will break at a given pressure, and the use of'this seal renders the use of a movable cap unnecessary thereby decreasing the cost of manufacture and adding greatly to the simplicity of the apparatus. I

.The size of the apparatus will depend on the conditions of service and each unit is complete in itself and independent of any external pipe or reservoir thereby adapting it for use in small stores, rooms and other places where the hydraulic system is. not available.

In the use of this extinguisher the vessel 5 having been filled with 'a suitable extinguishing liquid and the space or chamber- 6 between said casing and the shell 1 with a gas producing material the device is then suspended in any suitable location where it will remain indefinitely .ready for use. When the temperature in the vicinity of the device is raised beyond a predetermined point the heat causes the ammonia in the chamber 6 to become gas in a very few minvided utes owing to the small quantity exposed to the heat and the pressure of this gas thereby whereby it is spread out or considerable area, the spraying quantity of gas a very desirable feature produced forces the liquid in the casing 5 up and out of the tube 9 thereby breaking the closure 8 and permitting the stream of liquid to escape through the nozzle 10 and impinge on the lower face of said spreader 11 sprayed over a of the liquid being varied according to the shape of the lower face of the spreader.

It willthus be obvious that by placing the casing 5 within the shell 1 and forming it of non-heat conducting material the small it producing material contained in the space between the casing 5 and shell 1 will be much more quickly heated than would the entire contents of the shell 1 were this casing not used. Furthermore, it is undesirable that the liquid delivered from the nozzle be at its boiling point; rather the contrary being preferred so that premature volatilization shall not take place before the liquid may be delivered as such. It will thus beobvious that this double walled container renders the device very sensitive to a rising temperature and consequently greatly increases its efiiciency.

In filling or supplying the container carbon tetra-chlorid is poured into the opening 15 in sufiicient quantity to fill the inner receptacle or casing'5 and then a predetermined quantity of strong ammonia solution is poured in through this opening and this solution being lighter than the carbon tetrachlorid and not mixable with it overflows into the outer shell. The cap 16 is then screwed on and a piece of foil or other'suitable membrane is adjusted to close the nozzle 10.

While I have described my invention with more or less minuteness as regards details and as being embodied in certain precise forms, I do not desire to be limited thereto unduly any more than is pointed out in the claim. On the contrary, I contemplate all proper changes in form, construction and arrangement, the omission of immaterial elements and substitution of equivalents as circumstances may suggest or render expdient. i

I claim as my invention:

A fire extinguisher comprising two containers arranged one within the other and spaced apart, the outer container being closed at both ends, and the inner container permanently closed at its lower end an open at its upper end, said inner container terminating at its upper end below the top of said outer container and being filled with a fire extinguishing liquid, a filling opening in the top of said outer container positioned over the upper end of said inner container, the chamber formed between said containers having therein a substance for rapidly generating a pressure producing gas when heated, said substance being lighter than and not mixable with the extinguishing liquid whereby it will flow over the top of said inner container into the space between said containers, and a'distributing tube 'extending through the top of said outer container to a point near the bottom-0f the inner container.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

HOWARD W. DOUGHTY. Witnesses:

JOHN A. CRosmR, Ensm H. STORE. 

